Who established the regulations for the order and discipline of US troops in 1778?

The correct choice is Friedrich Von Steuben, who played a pivotal role in shaping the discipline and regulations of the Continental Army during the American Revolution. Arriving in America as a Prussian military officer, he implemented a comprehensive system of training that included tactics, discipline, and standard procedures for troops. His influence was particularly significant at Valley Forge, where he introduced a standardized drill manual, known as the "Regulations for the Order and Discipline of the Troops of the United States." This manual became the foundation for military training in the United States and had lasting impacts on the professionalism and effectiveness of the army.

General George Washington, while instrumental as a leader and commander, relied on Von Steuben's expertise to enhance the training and discipline of the troops. Colonel Henry Knox was primarily responsible for artillery and logistics rather than establishing regulations for troops. The Sergeant Major of the Army role, established much later, does not apply to the context of 1778 regulations and policies. Thus, Von Steuben's contributions were crucial for the development of military order at that time.